A Study on Extracting the Trend of Thin Ice Distribution in the Sea of Okhotsk Using Amsr-e and Amsr2 Data

Passive microwave radiometers onboard satellite can penetrate clouds and can monitor the global sea ice distribution on daily basis. It is not easy to extract sea ice thickness information from satellite data. In 2012, the authors have developed a method to detect thin ice area using the brightness temperature data derived from the passive microwave sensor AMSR-E onboard Aqua satellite. The basic algorithm is to use the brightness temperature scatter plots of AMSR-E 19GHz polarization difference (V–H) vs 37GHz V polarization. In May 2012, AMSR2, the successor of AMSR-E, were successfully launched by JAXA on board GCOM-W1 satellite. Recently, the authors have developed a new method to detect thin ice area using brightness temperature scatter plots of AMSR2 19GHz polarization difference (V-H) vs 19GHz V polarization. It worked quite well in the Sea of Okhotsk with both AMSR2 and AMSR-E data. The authors have calculated the thin ice distribution in the Sea of Okhotsk from 2003 to 2015 using the new method. The result suggested the reduction trend of total sea ice extent from 2003 to 2015 and the increasing trend of thin ice extent from 2009 to 2015.